You stare at waterfall for a minute or two, and then shift your gaze to its surroundings. What you now see appears to drift upward. These optical illusions occur because the brain is constantly matching its model of reality to signals from the body's sensors and interpreting what must be happening--that your brain must have moved, not the other; that downward motions is now normal, so a change from it must now be perceived as upward motion. The sensors that make this magic are of two kinds. Each eye contains about 120 million rods , which provide somewhat blurry black and white vision. These are the windows of night vision; once adapted to the dark, they can detect a candle burning ten miles away. Color vision in each eye comes from six to seven million structures called cones . Under ideal conditions, every cone can "see" the entire rainbow spectrum of visible color1s, but one type of cone is most sensitive to red, another to green, a third to blue. Rods and cones send their messages pulsing an average 20 to 25 times per second along the optic nerve. We see an image for a fraction of a second longer than it actually appears. In movies, reels of still photographs are projected onto screens at 24 frames per second, tricking our eyes into seeing a continuous moving picture. Like apparent motion, color1 vision is also subject to unusual effects. When day gives way to night, twilight brings what the poet T.S. Eliot called "the violet hour." A light levels fall, the rods become progressively less responsive. Rods are most sensitive to the shorter wavelengths of blue and green, and they impart a strange vividness to the garden's blue flowers. However, look at a white shirt during the reddish light of sunset, and you'll still see it in its "true" color1--white, not red. Our eyes are constantly comparing an object against its surroundings. They therefore observe the effect of a shift in the color1 of illuminating on both, and adjust accordingly. The eyes can distinguish several million graduations of light and shade... Visual illusions often take place when the image of reality is   _  . A) matched to six to seven million structures called cones. B) confused in the body's sensors of both rods and cones. C) interpreted in the brain as what must be the case. D) signaled by about 120 million rods in the eye.
C


(Question)
The seas and rivers are being poisoned by radioactive wastes, by chemical    discharges and by the dumping of dangerous raw swage . The air we breathe is polluted by smoke and fumes from factories and motor vehicles; even the rain is poisoned.    It's little wonder forests and lakes are being destroyed and everywhere wildlife is disappearing, and yet the destruction continues.    Governments and industries throughout the world are intensifying  their efforts to extract the earth's mineral riches and to destroy its living resources.    The great rain-forest and the frozen continents alike are seriously threatened, despite the warnings of the scientific community and the deep concern of millions of ordinary people.    In fact, we can create environmentally clean industries, use the power of the sun, wind and waves for our energy needs and manage the finite  resources of the earth in a way that will safeguard our future and protect all the rich variety of life-forms which share this planet with us. The main idea of the passage is that . A) the seas and rivers are being poisoned B) we can protect natural environments C) the natural world is under violent attack from man D) governments and industries should be responsible for the destruction of the natural world
(Answer)
C


Ques: Have you ever made contact with the creative spirit, that certain something hard to describe, but full of good--and sometimes great--ideas? It is more than an occasional great thought. When we feel the moving of the creative spirit, it brings to life a style of being: a lifetime filled with the desire to invent, to explore new ways of doing things, and to turn dreams into reality. That flash of inspiration is the final moment of a process marked by unique stages--the basic steps in creative problem-solving. The first stage is preparation, when you look for any information that might be important. It's when you let your imagination run free. But one barrier  is the inside voice of judgment that locks up our creative spirit within the limits of what we think acceptable. It's the voice that whispers to you, "They'll think I'm foolish," or "That will never work." But we can learn to recognize this voice of judgment and have the courage to discount its unhelpful advice. Once you have thought about all the relevant  pieces and pushed your mind to the limits, you can let the problem remain and take in all you have gathered. It's a stage when much of what goes on occurs outside your focused awareness. As the saying goes, "You sleep on it." We are more open to creative thoughts from the unknowing mind when we are not really thinking of anything. That is why daydreams are so useful in the search for creativity. Anytime you can just daydream and relax is useful in the creative process: a shower, long drives, a quiet walk, etc. With luck, daydreaming will lead to a light turning on above your head, when all of a sudden the answer will come to you as if from nowhere. This is the popular stage--the one that usually gets all the glory and attention, the moment that people sweat and long for, the feeling "This is it!" But the thought alone is still not a creative act. The final stage is translation, when you take your creative thought and transform it into action; it becomes useful to you and others. When does creativity become useful to us and others? A) When thought is turned into action. B) When people understand our ideas. C) When the popular stage is reached. D) When we think "This is it!".
Ans: A


Air travel makes some people very nervous. The crowds, the noise and flying itself can cause unease. But there are classes that people can take to help them defeat the fear of flying. And now we are going to talk about similar training for service dogs that suffer from the same problem. Service dogs almost never leave the side of the people they care for. You will see them working on buses, trains and other public transport systems. But the busy environment in an airport can trouble even the best trained working dog. People with disabilities depend on their dogs. They also need the dogs to remain calmly on duty on the airplane, even when the flight is not smooth. This takes special training. The Air Hollywood K9 Flight School is one place where such help can be found. The school has a piece of equipment that provides the sights, sounds and even the feel of an airplane in flight. It is called a flight simulator . The simulator was built for filming airplane scenes in movies. Sandy Alexander lives in Newport Beach, California. He has a disability that requires his two-year-old dog, Doc, to be always at his side. Mr. Alexander took the dog to the flight school to get him ready for plane trips. He says Doc did not like the bumpy  part of the flight simulation. "When that started he was pretty _ and looked up at me and wasn't sure what was gong on." "Dogs need to be exposed gradually and repetitively to stimulation, to the environment, to loud noises, to sounds and other dogs so that when this experience happens to them on a daily basis, they are able to act in a way that they are used to acting and don't get excitable," days dog trainer, Mary Segall. Dog owners who have attended the training say they now feel much more at ease about future flights. Their dogs also seem ready for take-off. The flight simulator  _  . A) can help people to learn how to fly an airplane B) was built for filming airplane scenes in movies C) can't provide the feel of an airplane in flight D) let service dog owners experience the thrill of flying

B